The present invention relates to a valve assembly for a hydraulic discharge device, in particular, a steering pump, comprising a flow control valve and a pressure-limiting valve.
In such valve assembly, the flow control valve serves for providing a predetermined fluid flow from the discharge device to an actuator. For example, when the valve assembly is used for controlling fluid flow from a steering pump to a steering gear, the fluid control valve is designed for limiting the fluid flow to the actuator to, e.g., no more than 8 1/min. The pressure-limiting valve serves for maintaining a predetermined pressure in the system, e.g., for preventing the pressure rise above 100.div.110 bar.
In known valve assemblies of this type, the flow control and pressure-limiting valves are structurally connected with each other, that is, both valves are combined in a single structural piece, with the pressure-limiting valve being located in the piston of the flow-control valve. The drawback of such a structure consists in that it manufacture and assembly are very expensive.
In other known valve assemblies of this type, the flow-control valve and the pressure-limiting valve are separate elements located in different cavities formed in the discharge device housing. In this case, additional channels need be formed in the housing to connect the two valves with each other. This also results in increased production cost of the valve assembly.
Accordingly, the object of the invention is a valve assembly of the above-mentioned type which can be produced easily and inexpensively, and which would have a high functional reliability.